Does the remaster come with the original port, like Bioshock and other remasters do?

For cereal? I was not expecting it too.

Yep, it just don't say that on the store page. But you get one copy for terminal cut and one copy for (legacy) when you buy it.

Just to clarify further, the originals are their own downloads with their own library entries?

Yes they are.

It should really be added to the Store page that this release of the game also gives you the original Legacy versions & their bonus extras... would be a lot easier than people asking if these things are available in the forums.